1. Field of the Invention
The present invention relates to a sealing arrangement for limiting or closing off the areas to be filled with a casting compound of a tension member composed of a bundle of individual elements arranged within a tubular sheathing, for example, a stay cable of a cable-stayed bridge.
The present invention also relates to a method of manufacturing the arrangement.
2. Description of the Related Art
In tension members as they are used in civil engineering, for example, tension members for prestressed concrete, stay cables for cable-stay bridges, or the like, usually several individual elements, such as, steel rods, steel wires or strands are combined into a bundle and are arranged within a tubular sheathing to protect the bundle against corrosion. In the area of the free length of the tension member, this tubular sheathing usually is composed of a sheathing tube of synthetic material, for example, polyethylene, and in the anchoring area, where the individual elements are spread apart for anchoring, the sheathing is composed of a steel pipe which expands or widens in a trumpet-shaped configuration.
In such tension members it is frequently necessary, for technical or economical reasons, to fill out certain areas along the length of the tension member, for example, the area of an anchoring system or a guide saddle, with a setting material, for ,example, cement mortar, synthetic resin mortar or synthetic resin, in order to obtain a bonding action or for placing the individual elements in the correct order or for supporting the individual elements against deflection forces, while the remaining areas, particularly the free length of the tension member, are not filled out in this manner, among other reasons, to reduce the weight. In order to limit or seal off these areas from each other and in order to prevent an unintentional flowing out of the filling material when it is injected, it is necessary to provide sealing arrangements. Such sealing arrangements are particularly necessary in stay cables of cable-stayed bridges at the upper anchoring system on the tower of the cable-stayed bridge, as disclosed in German Patent application 44 33 847 A1.
Particularly in the case of bundled tension members having a large number of individual elements, it is difficult to construct the sealing arrangements of the above-described type. These sealing arrangements not only must tightly surround each individual element, but they must also fully fill out the remaining annular space up to the inner wall surface of the sheathing, in order to ensure a reliable sealing action even with respect to injection materials which are present as thin liquids, particularly synthetic resin.